Project Summary/Abstract Some of the most common and disabling consequences of brain injury are deficits in cognition. In particular, disruption of attentional regulation reduces the efficiency and effectiveness of functions including learning, memory, problem-solving and goal management, leading to significant functional disability. Despite the importance of these problems, few effective interventions are available. The long-term goal of this research program is to develop and test novel neuroscience-based interventions for improving cognitive functioning. In order to achieve this goal, an important intermediate step is to understand the mechanisms that support treatment success, when they do occur. However, such mechanisms of cognitive improvement are currently poorly understood. The overall goal of this proposal is to elucidate mechanisms through which attention may be improved for patients with brain injury. Attention regulation occurs at a number of possible levels to control brain functioning, from guiding attention towards selected information from the 'top-down' based on explicit goals, to the most basic driving and sustaining of cognitive activity from the 'bottom-up.' The proposed projects will determine the neural and behavioral effects of interventions designed to train different levels of attentional control, in randomized controlled studies for individuals with brain injury. Aim 1. To determine the neural, neurocognitive and functional effects of a theory-driven, strategy-based intervention that trains goal-oriented attention with intensive application through accomplishment of personally relevant projects. Hypothesis: Participation in the experimental intervention will enhance functioning in complex 'real-life' settings, relative to an educational intervention matched for time and attention. Aim 2. To determine the neural, neurocognitive and functional effects of a computer-assisted game-based protocol designed to intensively train the target process of re-direction of selective attention when distracted. Hypothesis: Participation in the experimental intervention will result in improvements in attention and working memory (reflecting protection from distraction), relative to a comparison intervention matched for time and computer usage. Aim 3. To determine the neural, neurocognitive and functional effects of a computer-assisted training task that targets basic tonic and phasic attention functions. Hypothesis: Participation in the experimental intervention improves sustained attention, relative to a comparison intervention matched for time and computer usage. Each study will also investigate to what extent effects transfer to higher and lower levels of function and domains of cognitive functioning that are not explicitly trained; to what extent neural measures help to explain variability in behavioral effects; and to what extent effects are maintained at 6 months follow-up. Conclusions. By applying three different intervention approaches we will be able to systematically determine effects at multiple levels at which attention regulates brain functioning. This information will help build a neuroscience foundation for the development of novel interventions to improve cognitive functioning with potentially wide-ranging impacts for individuals with brain injury.